Develop a resource which will provide researchers with environmental quality data at a level of refinement and completeness not prevously available. At the completion of the first year, the Department of Environmental Protection, State of New Jersey, will present the NCI with completed questionnaires for all major water purveyers, along with magnetic tapes containing supplementary water quality information. These data will facilitate the following analyses: the first statewide examination of historical chlorination practices; an examination of the relationship between chlorination and trihalomethane concentration in finished water; and an investigation of the relationship between source pollution and finished water quality.